| 摘要 |
The method and associated apparatus of the present invention decodes digital signals by appropriately weighting the respective noise portions of the two phase segments generated by the detector, such as an APD in an optical communications system, such that the digital signal can be reliably decoded despite the presence of multiplicative noise induced by the detector. The detector detects a digitally encoded communications carrier signal having a waveform defining first and second portions. The detector then generates an electrical signal in response to the digitally encoded communications carrier signal. The electrical signal has two phase segments, namely, one phase segment corresponding to the first portion of the digitally encoded communications carrier signal and another phase segment corresponding to the second portion of the digitally encoded communications carrier signal. Each phase segment also includes a respective noise portion. The optical decoding method and apparatus determines a weighting factor based upon the respective noise portions of the two phase segments. Thereafter, at least one phase segment is weighted by the weighting factor. For example, the noisier phase segment can be attenuated by the weighting factor. A decoder can then identify the logic level of the digital signal based upon the two phase segments as weighted by the weighting factor.
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